The concepts, designing procedures and the like of security devices for defending humans from harm when a machine fails or humans make a mistake are described, for instance, in JIS B 9705-1: SAFETY OF MACHINES, Safety-Related Portions of Control System Part I: General Rules for Designing. In large-scale systems such as general industrial machines or nuclear facilities, security is provided, based on the recognition that humans make mistakes, to minimize intervention by humans. If intervention by humans is required by any means, expert persons, who have been fully trained, are allowed to operate the machines for security.
In contrast, in the automotive traffic system, although there is a licensing system, safety is generally secured based on observance of traffic rules and much attention of non-professional drivers. The method of securing the automotive traffic system generally has been traffic controls and education of the drivers.
Recently, to reduce careless mistakes of drivers, a sensor system has been loaded on a vehicle to alert the driver upon the detection of obstacles around the vehicle. It is becoming more and more popular, and further a safe driving support system has been developed which detects dangerous situations at places where traffic accidents frequently occur with sensors installed on the roadside and provides the driver with information concerning the dangerous situations.
The present invention relates to a safe driving support system which delivers information concerning dangerous situations from a system installed on a roadside to vehicles and drivers. With this type of system, if erroneous information indicating that there is no danger is delivered from the roadside system to a vehicle and a driver when there is a danger, and when the driver believes that the information is correct, the driver falls in a dangerous situation, which is problemsome. This invention was made for preventing occurrence of the problems as described above.